Docker Tutorial

Here we covers the basics and advanced concepts of Docker.

Prior to Docker, many users faced the problem that a particular code was running on the developer’s machine but not on their computer. A Docker container is a centralized platform for packaging, deploying, and running applications. As such, the main reason for developing Docker was to make it easier for developers to build applications, ship them into containers, and deploy them anywhere.

Docker was first released in March 2013. It’s used in the Deployment stage of the software development life cycle, so it can resolve deployment issues efficiently.

Docker

This is an open-source centralized platform for creating, deploying, and running apps. Docker uses containers on the host’s operating system to run applications. Instead of creating a whole virtual operating system, containers allow applications to run on the same Linux kernel as a host computer. We can use containers in development, test, and production to make sure our app works.

There’s Docker client, Docker server, Docker machine, Docker hub, and Docker composes.

Let’s talk about Docker containers and virtual machines.

Docker Containers

Using Docker containers, developers can package up an application with all its libraries and dependencies and ship it as a single file. They’re the lightweight alternative to virtual machines. With docker containers, you don’t have to allocate RAM or disk space for applications. They just create storage and space based on the application.

Virtual Machine

The operating systems in which virtual machines run are called virtualized operating systems. A virtual machine lets us install and use other operating systems at the same time (Windows, Linux, and Debian). A virtualized operating system can run programs and do things like a real one.

Containers Vs. Virtual Machine

Why Docker?

You should use Docker if you’re a developer or a system administrator.

With Docker, you don’t have to worry about setup or dependencies.

Docker runs and manages apps in isolated containers for better compute density.

Companies use Docker to build faster, more secure agile software delivery pipelines.

Since Docker isn’t just used for deployment, it’s also great for development, so we’re able to increase customer satisfaction efficiently.

Advantages of Docker

• The container runs in seconds instead of minutes.
• Less memory is used.
• Lightweight virtualization.
• Applications can be run without a full operating system.
• To reduce risk, it uses application dependencies.
• You can share your container with others using Docker’s remote repository.
• Continuous deployment and testing are provided.

Disadvantages of Docker

• Due to the additional layer, it makes things more complicated.
• It’s hard to manage a lot of containers in Docker.
• The Docker container lacks some features, such as self-registration, self-inspection, and copying files from the host to the container.
• Using Docker for applications that need a rich graphical interface is not a good idea.
• An application designed for Windows won’t run on Linux if it’s designed to run in a Docker container.

Docker Engine

• This is a client-server application with the following major components.
• Servers are long-running programs called daemons.
• In the REST API, programs can talk to the daemon and tell it what to do.
• Client with a command line interface.

Prerequisite

To learn Docker, you need to know Linux and programming languages like Java, PHP, Python, Ruby, etc.